The present invention relates, in general, to a cap set on the mouth of a liquid container so as to open or close the mouth as desired and, more particularly, to a cap designed to allow atmospheric air to be introduced into the liquid container through the cap when liquid is discharged from the container through the cap.
As well known to those skilled in the art, a conventional cap for liquid containers is designed in that it is normally tightened to the single mouth of a liquid container to close the mouth, and is selectively removed from the mouth to open the mouth when it is desired to discharge liquid from the container. After the cap is removed from the mouth of the container, the container is properly leaned to a side so as to allow a desired amount of liquid to be discharged from the container through the open mouth. When liquid is discharged from the container through the open mouth as described above, negative pressure corresponding to the volume of discharged liquid is formed within the container. In order to compensate for the negative pressure within the container, atmospheric air is continuously introduced into the container through the same mouth during such a liquid discharging action. However, the mouth of the container provides only one passage, and so discharged liquid unevenly flows out of the mouth and gushes violently since it inevitably encounters atmospheric air current flowing into the container through the same mouth. Therefore, people sometimes fail to smoothly discharge liquid from the mouth of the container into a desired cup, but may spill some liquid outside the cup.
In an effort to overcome the above-mentioned problem experienced while discharging liquid from the mouth of a conventional liquid container, another liquid container, designed to prevent such an encounter of outlet liquid with inlet atmospheric air within the mouth and to prevent uneven flow of outlet liquid or a violent gush of the liquid from the mouth, was proposed. In this proposed liquid container, a mouth, normally sealed with a cap, is formed at a side of the container, while an air inlet opening is formed at the other side opposite to the mouth. When liquid is discharged from the leaned container through the open mouth, atmospheric air is separately introduced into the container through the air inlet opening, thus smoothly flowing into the container without encountering the outlet liquid. However, this liquid container is problematic in that it forces a manufacturer to separately form the air inlet opening on the container in addition to the mouth of the container during the process of producing the containers. This complicates the container production process and increases the production cost, and reduces productivity while producing liquid containers. Another problem of the container resides in that it fails to achieve a desired sealing effect for preserving the liquid in a fresh state. In addition, the liquid container, having such a separate air inlet opening in addition to the mouth, is limited in its application since it is very difficult to form such an air inlet opening on some containers having a narrow neck, such as bottles.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a cap for liquid containers, which is designed to allow liquid to be smoothly discharged from a liquid container through the mouth of the container while allowing atmospheric air to smoothly flow into the container through the mouth without encountering the discharged liquid.
Another object of the present invention is to provide a cap for liquid containers, which is designed to allow a user to selectively open the mouth of a liquid container to discharge liquid from the container through the mouth and to tightly close the mouth so as to achieve a desired sealing effect for preserving the liquid left within the container in a fresh state.
A further object of the present invention is to provide a cap for liquid containers, which is designed to allow some liquid, left around the mouth of a liquid container after a liquid discharging action, to be naturally recovered into the container by gravity.
In order to accomplish the above objects, the present invention provides a cap for liquid containers, comprising: a mounting part mounted to the mouth of a liquid container, the mounting part having a cylindrical shape with an internal thread and being tightened to an external thread formed on the mouth of the liquid container at the internal thread; a liquid discharging part extending from the top of the mounting part upwardly, and used for discharging liquid from the container, the liquid discharging part comprising a hollow cylindrical sidewall and a top wall integrated along the top edge of the cylindrical sidewall so as to cover the top of the sidewall, with a liquid outlet opening formed at a portion of the sidewall and an air inlet opening formed at another portion of the sidewall opposite to the liquid outlet opening, and a partition wall vertically extending from the lower surface of the top wall downward within the liquid discharging part, thus partitioning the interior of the liquid discharging part into a liquid passage and an air passage; and an openable top cover connected to a side of the mounting part, and used for covering and protecting the liquid discharging part.